Photocatalytic Performance Of g-C3N4 Research Articles

MXene quantum dots decorated g-C3N4/BiOI heterojunction photocatalyst for efficient NO deep oxidation and CO2 reduction

The photocatalytic performance of g-C3N4 is greatly limited by the severe charge recombination due to its s-triazine unit structure. Hence, enhancing the separation of photogenerated carriers is the pivotal factor for high-efficiency photocatalysis of g-C3N4. In this work, we construct a MXene quantum dots (MQDs) decorated BiOI/g-C3N4p-n heterojunction photocatalyst. The interfacial charge separation and transfer are substantially promoted, due to the synergistic effect of the internal electric field (IEF) of BiOI/g-C3N4 heterojunction and strong electron-withdrawing capability of MQDs. Furthermore, the introduction of BiOI with a low band gap and MQDs with large specific areas and rich surface terminals lead to enhanced light absorption and active sites. As a result, the ternary g-C3N4/MQDs/BiOI photocatalyst achieves a much higher NO removal rate of 42.23 % and discharges less NO2 intermediate than the individual and binary ones. Meanwhile, the g-C3N4/MQDs/BiOI photocatalyst also exhibits the most effective CO2 photoreduction, with a CO production rate of 57.8 μmol·g−1·h−1 and a CH4 production rate of 3.6 μmol·g−1·h−1, surpassing all other photocatalysts in this study. In addition, the designed composite photocatalyst shows remarkable stability. The photocatalytic mechanisms are studied by the trapping experiment and in-situ Fourier Transform Infrared (FTIR) Spectra. This work paves a new avenue for enhancing charge separation and thus improving performances of g-C3N4-based photocatalysts by integrating a p-n heterojunction and a co-catalyst, which would accelerate commercial deployment of emerging photocatalysts.

One-pot synthesis of g-C3N4/N-doped CeO2 nanocomposites and their potential visible light-driven photocatalytic degradation of methylene blue dye.

In the pursuit of efficient photocatalytic materials for environmental applications, a new series of g-C3N4/N-doped CeO2 nanocomposites (g-C3N4/N-CeO2 NCs) was synthesized using a straightforward dispersion method. These nanocomposites were systematically characterized to understand their structural, optical, and chemical properties. The photocatalytic performance of g-C3N4/N-CeO2 NCs was evaluated by investigating their ability to degrade methylene blue (MB) dye, a model organic pollutant. The results demonstrate that the integration of g-C3N4 with N-doped CeO2 NCs reduces the optical energy gap compared to pristine N-doped CeO2, leading to enhanced photocatalytic efficiency. It is benefited from the existence of g-C3N4/N-CeO2 NCs not only in promoting the charge separation and inhibits the fast charge recombination but also in improving photocatalytic oxidation performance. Hence, this study highlights the potential of g-C3N4/N-CeO2 NCs as promising candidates for various photocatalytic applications, contributing to the advancement of sustainable environmental remediation technologies.

Insights into the structural variation and photocatalytic performance of g-C3N4 via doping N, O and S atoms

Insights into the structural variation and photocatalytic performance of g-C3N4 via doping N, O and S atoms

Effect of P and Ce co-doping on the photocatalytic performance of g-C3N4: Experimental and theoretical studies

Element doping strategies are commonly employed to achieve effective photocatalysts. In this work, a novel form of P and Ce co-doped g-C3N4 nanosheets was synthesized using a one-step thermal polymerization technique, exhibiting remarkable efficiency in the degradation of organic pollutants under visible light. The prepared catalysts underwent comprehensive characterization through XRD, FT-IR, SEM, TEM, BET, XPS, UV–vis, PL, and electrochemical testing. The electronic and optical properties of the catalysts were further elucidated using first-principles density functional theory (DFT). In the photocatalytic experiment of degrading Rhodamine B (RhB), the photocatalytic ability of g-C3N4 nanosheets was improved at different degrees, among which g-C3N4 nanosheets co-doped with P and Ce showed the highest photocatalytic activity, with a degradation efficiency of 90.58 % for RhB. Furthermore, the photocatalytic mechanism was confirmed through free radical capture experiments. This study presents a novel approach for the development of efficient photocatalysts to remove pollutants.

Photocatalytic degradation of sulfonamides in suspensions of coral-like graphene carbon nitride with nitrogen vacancies

Sulfonamides (SNs) belong to a category of broad-spectrum antibiotics, which have attracted growing concerns owing to the adverse effects on ecosystem. In this paper, coral-like graphitic carbon nitrides with nitrogen vacancies were prepared by polymerization of melamine in the presence of NH4Cl, and the effect of NH4Cl amount on the structure and photocatalytic performance of g-C3N4 in degradation of sulfonamide antibiotics such as sulfamethoxazole (SMX), sulfadiazine (SDZ) and sulfathiazole (STZ) was systematically studied. It was found that the addition of NH4Cl results in the formation of coral-like g-C3N4 with nitrogen vacancies, and optimal photocatalyst (PCN-1 sample) prepared with a melamine to NH4Cl mass ratio of 1:1 showed the highest photocatalytic activity towards SNs degradation due to the quick electron-hole migration, efficient separation capacity and excellent photoelectric properties. The electron paramagnetic resonance (EPR) technique was used to determine the reactive oxygen species (ROSs) that are responsible for the degradation of SNs, and the detailed degradation pathway of STZ was proposed according to the identification of the intermediates by liguid chromatography-high resolution mass spectrometry (LC-HRMS).

Density functional theory-based modeling of the half-metallic g-C3N4/CoN4 heterojunction for photocatalytic water splitting reaction.

Using density functional theory (DFT), we have investigated the structural, optical, electronic and magnetic properties of a graphitic carbon nitride (g-C3N4) and CoN4 composite to explore the effect of the heterojunction on the photocatalytic performance of g-C3N4. The structure of g-C3N4 is modified while complexing with CoN4 and the corresponding stabilization is confirmed through adhesion energy calculation. The phonon spectra analysis furthermore guaranteed the lattice-dynamic stability of the CoN4 bulk and the CoN4 slab. Pristine g-C3N4 is a wide band gap semiconductor, which becomes half metallic upon CoN4 inclusion. The metallicity in the g-C3N4/CoN4 composite originates from the spin down channel, keeping the spin up channel in a semiconducting state. The charge density analysis and work function calculation suggest a substantial amount of charge transfer from g-C3N4 to the CoN4 unit in the g-C3N4/CoN4 heterojunction. The model heterojunction of the g-C3N4/CoN4 composite can enhance the utilization ratio of visible light for the g-C3N4 photocatalyst. In g-C3N4/CoN4, the valence band maximum (VBM) has a more positive potential compared to O2/H2O (+1.23 V) on the normal hydrogen electrode (NHE) scale. However, the conduction band minimum (CBM) displays a more negative potential compared to H+/H2 (0 V) on the NHE scale. The details of the band structure, density of states and band edge position determining calculations confirm that the g-C3N4/CoN4 composite forms a type 1 heterojunction, making it a suitable photocatalyst for water splitting reaction. The practical application of the g-C3N4/CoN4 heterostructure as a photocatalyst was substantiated in the presence of polar solvent (water) by calculating the band gap, charge transfer interaction and charge density difference. There is a significant decrease of charge transfer and thereby charge density difference in the g-C3N4/CoN4 heterojunction in the presence of water; however, it still holds potential for use as a photocatalyst for water splitting reaction. The state-of-the-art theoretical modeling of the g-C3N4/CoN4 heterojunction is the first theoretical study incorporating the CoN4 crystal.

Preparation of RE/g-C3N4 Photocatalysts by Thermal Polycondensation Method and Its Properties

Graphite phase carbon nitride photocatalysts (RE/g-C3N4) doped with different rare earths (RE=La, Ce, Sm, Nd, Eu) were prepared by thermal polycondensation method using rare earth metal nitrate and melamine as raw materials. The photocatalytic performance of RE/g-C3N4 was studied through using photo-degradation reaction of methylene blue (MB) as the evaluation model. The effects of calcination temperature, rare earth elements type and doping ratio on the photocatalytic performance of g-C3N4 were studied. The microstructure of the samples were characterized by FESEM, XRD, UV-Vis, etc. The results show that RE doping can refine the grains and enhance the absorption of visible light. The performance of rare earth doped samples have a significantly improved compared with pure g-C3N4. The performance of La doped samples was better than that of Ce, Sm, Nd and Eu doped g-C3N4. As the temperature increases, the photocatalytic activity of La/g-C3N4 samples increases. When the La doping ratio is 4.0%, the calcination temperature is 590 °C, the degradation rate of The La/g-C3N4 photocatalyst to MB is up to 98.0% within 4 h under visible light irradiation.

Efficient photocatalytic H2 production of g-C3N4 using nickel (II) functional complex as promoter

With the increasingly prominent energy and environmental problems, the construction of sustainable development, green environmental protection and new efficient energy system has become the focus of the world's attention. Photocatalytic hydrogen production technology is an important way to solve energy and environmental problems. The key to realizing the visible light catalytic water hydrogen production technology effectively lies in the selection of photocatalytic materials, graphite phase carbon nitride (g-C3N4) is an important photocatalyst. However, the photocatalytic performance of g-C3N4 is severely limited by the high recombination rate of photogenerated electron-hole pairs. Functional complex has a matching band gap with carbon nitride to form heterojunction structure, which can effectively reduce the photogenic carrier recombination and improve the catalytic hydrogen production performance. For this reason, the functional complex [Ni2(Medpq)2(BPDA)·2H2O] (BPDA = 4,4′-Biphthalic Anhydride, Medpq = 2-methyldipyrido[3,2-f:2′,3′-h]quinoxaline) was synthesized by a hydrothermal process. The matching band gap between [Ni2(Medpq)2(BPDA)·2H2O] and g-C3N4 forms heterojunction structure, which effectively solve the defect of low utilization rate of light energy and improve the catalytic hydrogen production performance of g-C3N4. The experiment proved that complex/g-C3N4 photocatalytic rates of hydrogen production 2054.13 μmol·h−1·g−1, about 5.04 times that of pure g-C3N4 (407.56 μmol·h−1·g−1), thus high-performance of the hydrogen production from water decomposition was realized.

Insight into the effect of Li/P co-doping on the electronic structure and photocatalytic performance of g-C3N4 by the first principle

In recent years element doping has been considered an essential method for developing low-cost and highly efficient graphitic carbon nitride (g-C3N4) photocatalysts for environmental remediation. In this work, we have synthesized Li and P co-doped g-C3N4 nanosheet (Li/P-g-C3N4) by a facile calcination process for the methylene blue (MB) dye degradation. With increased visible light (VL) absorption, improved electron-hole (e-/h+) pair separation, and larger surface area, the dye degradation rate constant (k) for Li/P-g-C3N4 is approximately 2.6 times faster than g-C3N4 under visible light. The density functional theory (DFT) calculation has also confirmed that Li and P co-doping into the g-C3N4 narrowed the bandgap, increased the photogenerated e-/h+ delocalization, and increased the charge transfer (CT) rate. Hence, the combined effect of metal and non-metal co-doping is the reason behind the outstanding photocatalytic efficiency of the Li/P-g-C3N4. The current study expands the performance window for metal/non-metal co-doped g-C3N4 while maintaining excellent quality.

Synthesis and photocatalytic performance of g-C3N4/MeTMC-COP composite photocatalyst.

Covalent organic polymers have excellent application prospects in photocatalysis due to their excellent visible light absorption and structural designability. However, their fast recombination efficiency and complex preparation process limit their applications. Because of the above problems, this paper used urea to prepare g-C3N4 by high-temperature thermal polymerization and prepared g-C3N4 composite photocatalyst loaded with MeTMC-COP (g-C3N4/MeTMC-COP) by hydrothermal method. The photocatalytic hydrogen generation and photocatalytic degradation capabilities of composite photocatalysts with various mass ratios were investigated by characterizing the catalyst and using the organic dye Rhodamine B (RhB) as the pollutant. According to the research, the specific surface area of the g-C3N4/MeTMC-COP composite may reach 40.95m2g-1 when the mass ratio of g-C3N4 and MeTMC-COP is 3:1 (25.22m2g-1). It can offer more active sites for the photocatalytic process, and because the fluorescence peak intensity is the lowest, it has the lowest photogenerated electron-hole recombination efficiency. In comparison to g-C3N4, 3:1g-C3N4/MeTMC-COP can breakdown rhodamine B up to 100% after 75min of light irradiation; its photocatalytic hydrogen generation efficiency is 1.62 times that of g-C3N4, and the hydrogen evolution rate is 11.8μmolg-1h-1.

Single-Step Synthesis of Graphitic Carbon Nitride Nanomaterials by Directly Calcining the Mixture of Urea and Thiourea: Application for Rhodamine B (RhB) Dye Degradation

Recently, polymeric graphitic carbon nitride (g-C3N4) has been explored as a potential catalytic material for the removal of organic pollutants in wastewater. In this work, graphitic carbon nitride (g-C3N4) photocatalysts were synthesized using mixtures of low-cost, environment-friendly urea and thiourea as precursors by varying calcination temperatures ranging from 500 to 650 °C for 3 h in an air medium. Different analytical methods were used to characterize prepared g-C3N4 samples. The effects of different calcination temperatures on the structural, morphological, optical, and physiochemical properties of g-C3N4 photocatalysts were investigated. The results showed that rhodamine B (RhB) dye removal efficiency of g-C3N4 prepared at a calcination temperature of 600 °C exhibited 94.83% within 180 min visible LED light irradiation. Photocatalytic activity of g-C3N4 was enhanced by calcination at higher temperatures, possibly by increasing crystallinity that ameliorated the separation of photoinduced charge carriers. Thus, controlling the type of precursors and calcination temperatures has a great impact on the photocatalytic performance of g-C3N4 towards the photodegradation of RhB dye. This investigation provides useful information about the synthesis of novel polymeric g-C3N4 photocatalysts using a mixture of two different environmentally benign precursors at high calcination temperatures for the photodegradation of organic pollutants.

Recent Advances in g-C3N4-Based Materials and Their Application in Energy and Environmental Sustainability

Graphitic carbon nitride (g-C3N4), with facile synthesis, unique structure, high stability, and low cost, has been the hotspot in the field of photocatalysis. However, the photocatalytic performance of g-C3N4 is still unsatisfactory due to insufficient capture of visible light, low surface area, poor electronic conductivity, and fast recombination of photogenerated electron-hole pairs. Thus, different modification strategies have been developed to improve its performance. In this review, the properties and preparation methods of g-C3N4 are systematically introduced, and various modification approaches, including morphology control, elemental doping, heterojunction construction, and modification with nanomaterials, are discussed. Moreover, photocatalytic applications in energy and environmental sustainability are summarized, such as hydrogen generation, CO2 reduction, and degradation of contaminants in recent years. Finally, concluding remarks and perspectives on the challenges, and suggestions for exploiting g-C3N4-based photocatalysts are presented. This review will deepen the understanding of the state of the art of g-C3N4, including the fabrication, modification, and application in energy and environmental sustainability.

Role of dopants and defects on the photocatalytic performance of g-C3N4 under visible light and sub-band gap excitation

Here, we report the photocatalytic (PC) activity of graphitic carbon nitride (g-C3N4) doped with potassium (K), magnesium (Mg), and boron (B) under visible (>390 nm), green (532 nm), and red (660 nm) light. Doped g-C3N4 has an improved band structure, high carrier density, and tunable band-edge absorption as compared to pure g-C3N4. An atomic force microscope shows a decrease in layer thickness that follows the order: g-C3N4 > K/g-C3N4 > Mg/g-C3N4 > B/g-C3N4. The evolution of nitrogen vacancies in doped g-C3N4 was identified via x-ray photoelectron spectroscopy (XPS) and CHNS/O analyses. The red-shift in the absorption spectrum of K/g-C3N4 and the emission spectrum of B/g-C3N4 is caused by the band gap renormalization (BGR) effect. Quantum confinement and a possible Burstein–Moss (BM) effect both contribute to the spectral blue shift in the absorption spectra of Mg/g-C3N4 and B/g-C3N4. The BM effect, quantum confinement, and dopant-induced lattice strain might all alter the band structure and move the conduction band edge away from the valence band zone centre, causing an above band gap emission in K/g-C3N4 and Mg/g-C3N4. All samples degraded methylene blue (MB) under visible light with outstanding results, but they responded poorly to methyl orange (MO) and rhodamine B (RhB). With 83.59% MB degradation at a rate constant of 1.1 × 10−2 min−1, Mg/g-C3N4 recorded the best PC, which was three times quicker than g-C3N4 (3.7 × 10−3 min−1). When compared to g-C3N4, the doped samples’ current density (both anodic and cathodic) and carrier density were almost two times greater. The mechanism demonstrated how active edge sites, defects, and dopants contributed to the remarkable PC activity in the doped samples.

Insights into the photocatalytic mechanism of S-scheme g-C3N4/BiOBr heterojunction

The energy band alignment and photocatalytic performance of g-C3N4/(0 0 1)-BiOBr heterojunction are studied based on the first-principles HSE06 hybrid density functional method. Our results show that g-C3N4 and BiOBr are staggered near the forbidden band of the heterojunction. The built-in electric field (BEF) is formed with the direction from the g-C3N4 surface to the BiOBr surface. Under visible light irradiation, the existence of BEF makes the photogenerated electrons in the conduction band minimum (CBM) of BiOBr migrate across the interface region of g-C3N4/(0 0 1)-BiOBr heterojunction to reach the valence band maximum (VBM) of g-C3N4 to achieve the effective separation of photogenerated electron-hole pairs. g-C3N4/(0 0 1)-BiOBr heterojunction is an S(step)-scheme photocatalytic mechanism and a large number of photogenerated electrons come from the BiOBr will greatly improve the hydrogen production activity in the g-C3N4 surface, which is consistent with the previous experimental observations. Moreover, we predict that g-C3N4/(0 0 1)-BiOBr heterojunction has better hydrogen production efficiency and photocatalytic performance than g-C3N4/(0 0 1)-BiOCl heterojunction. Our work can provide an effective scheme and theoretical supports for the design of novel S-scheme heterojunction photocatalysts.

Impact of graphene oxide on visible light photocatalytic performance of graphene oxide/graphitic carbon nitride three-dimensional structure composites

ABSTRACT The non-metallic catalyst graphitic carbon nitride (g-C3N4) has attracted a significant amount of attention due to its excellent photocatalytic performance. The photocatalytic performance of g-C3N4 has been further enhanced by the incorporation of graphene oxide (GO) as a composite catalyst. However, the enrichment and recovery of these two-dimensional composites after photocatalysis is still a difficult challenge. In this work, a visible light responsive graphene oxide/graphitic carbon nitride coated sponge three-dimensional composite (PU-GO/g-C3N4) was prepared by electrostatic self-assembly using polyurethane sponge (PU) as a skeleton and g-C3N4 as a photocatalyst. The degradation rate of rhodamine B (RhB) under visible light was used as an index to evaluate the photocatalytic performance of PU-GO/g-C3N4. The results demonstrate that during the photocatalytic degradation of RhB by PU-GO/g-C3N4, g-C3N4 is the main photocatalyst, while the holes and the superoxide radicals generated by electron excitation are the main agents. As a bridge connecting PU and g-C3N4, GO improves the agglomeration phenomenon of g-C3N4 on PU. Meanwhile, GO has excellent carrier mobility and inhibits the recombination of photogenerated electrons and holes. Moreover, the presence of GO enhances the absorption of light and dyes. Overall, the addition of GO effectively enhances the photocatalytic performance of PU-GO/g-C3N4 due to it enhances dye absorption, improves light energy utilization rate, and expedites transfer of photogenerated electrons. After 5 cycles, PU-GO/g-C3N4 still exhibits an RhB degradation rate of 92.06%, demonstrating good stability and recycling performance. This material shows great promise for practical environmental remediation applications.

Photocatalytic Performance of Alkaline Activated Graphitic Carbon Nitride Under Blue LED Light

Graphitic carbon nitride (g-C3N4) is a metal-free photocatalyst with visible light response. However, the disadvantages limit its application in a wider range, such as its small specific surface areas, fewer active sites, narrow visible light absorption range and high photogenic carrier recombination. In this paper, NaOH was used as activator for alkaline activation of g-C3N4. The phase composition, micromorphology, surface chemical state and optical properties of g-C3N4 after activation were tested. The photocatalytic performance of g-C3N4 over organic dyes was also tested. The results showed that Na+ entered the interlayers of g-C3N4, expanding the spaces between layers. The specific surface area and pore volume of powder were increased. The active sites were increased. The band gap was decreased, and the photogenic carrier recombination was reduced. Alkaline activated g-C3N4 had better adsorption and degradation performance over rhodamine B and methyl orange than inactivated g-C3N4. Therefore, the alkaline activated g-C3N4 promotes its further application in the field of wastewater treatment. This work sheds light on the material modification through a simple method with the aim to efficiently use solar energy.

Synthesis of g-C3N4/NiO-carbon microsphere composites for Co-reduction of CO2 by photocatalytic hydrogen production from water decomposition

In this paper, a g-C3N4/NiO/corn straw derivative carbon microsphere composite photocatalyst was successfully prepared. Photoelectric studies show that a heterojunction was formed between g-C3N4 and NiO nanosheets, and the graphitized carbon microspheres were successfully modified on g-C3N4 and NiO nanosheets. The heterostructure between g-C3N4 and NiO works synergistically with the conductivity of carbon microsphere, resulting in H2 production and CO2 reduction in photocatalysis. Photocatalytic experiments show that the photocatalytic performance of g-C3N4/NiO/carbon microsphere composite is enhanced, and the highest H2 production rate was 36–58 times higher than that of pure g-C3N4. In the presence of CO2 gas, H2 production and CO2 reduction occur simultaneously. The possible mechanism of H2 production combined with CO2 reduction photocatalysis is analyzed from the perspective of thermodynamics and kinetics. The g-C3N4/NiO/carbon microsphere composite has a stronger H2 evolution performance than CO2 reduction performance. The change in free energy (ΔG) for the conversion of CO* to free CO gas is 0.52 eV, and CO release is the key step affecting the synergistic reduction of CO2 by H2. This study provides new strategies for the synergistic reduction of CO2 by photocatalytic technology for H2 production.

Photocatalytic performance of g-C3N4/Bi2S3/MWCNT ternary nanocomposite

Graphite-like carbon nitride (g-C3N4), has gained significant attention in the field of photocatalytic dye degradation during the past decade, owing to its simple preparation method and visible light response. In this study, g-C3N4/Bi2S3/MWCNT ternary heterostructure was prepared via a simple hydrothermal method, and its photocatalytic performance was compared with g-C3N4, Bi2S3, and g-C3N4/Bi2S3 heterostructures, using malachite green dye as a test pollutant. The result showed that g-C3N4/Bi2S3/MWCNT heterostructure photocatalyst exhibit improved photocatalytic activity, compared to other catalysts, owing to the improved electron-hole separation efficiency and strong visible light absorption. The study offers a simple way to develop g-C3N4/Bi2S3/MWCNT visible-light-driven ternary heterostructure for dye wastewater treatment.

Improvement in Structure and Visible Light Catalytic Performance of g-C3N4 Fabricated at a Higher Temperature

A highly-efficient graphitic carbon nitride (g-C3N4) photocatalyst for visible light photodegradation of rhodamine B (RhB) and methyl orange (MO) simulating dyeing wastewater was synthesized by the thermal polycondensation of melamine. The photocatalysts were characterized by TG-DTG-DSC, XRD, EA, XPS, FT-IR, SEM, TEM, BET, PL and UV-vis DRS. The results showed that the photocatalytic performance of g-C3N4 at a higher calcination temperature was significantly enhanced, and its photocatalytic activities for the photodegradation of RhB and MO were remarkably improved by 64.91% and 41.83%, respectively, which was mainly attributed to the satisfactory crystallinity, stable graphene-like structure, large surface area, and excellent optical properties. It was found that •O2− radicals and •OH radicals were the main active species for the photodegradation process by the free radicals trapping experiments and ESR analysis. The photodegradation mechanism of g-C3N4 was proposed predicated using the characterization results.

Highly Efficient Ag3PO4/g-C3N4 Z-Scheme Photocatalyst for Its Enhanced Photocatalytic Performance in Degradation of Rhodamine B and Phenol.

Ag3PO4/g-C3N4 heterojunctions, with different g-C3N4 dosages, were synthesized using an in situ deposition method, and the photocatalytic performance of g-C3N4/Ag3PO4 heterojunctions was studied under simulated sunlight conditions. The results revealed that Ag3PO4/g-C3N4 exhibited excellent photocatalytic degradation activity for rhodamine B (Rh B) and phenol under the same light conditions. When the dosage of g-C3N4 was 30%, the degradation rate of Rh B at 9 min and phenol at 30 min was found to be 99.4% and 97.3%, respectively. After five cycles of the degradation experiment for Rh B, g-C3N4/Ag3PO4 still demonstrated stable photodegradation characteristics. The significant improvement in the photocatalytic activity and stability of g-C3N4/Ag3PO4 was attributed to the rapid charge separation between g-C3N4 and Ag3PO4 during the Z-scheme charge transfer and recombination process.